New α-decaying neutron deficient isotopes197Rn and200Fr

New neutron-deficient isotopes,197Rn,197mRn, and200Fr have been produced and identified on the basis of genetic correlations in the166Er(36Ar,5n)197Rn (Elab=186, 200 MeV), and169Tm(36Ar,5n)200Fr (Elab=186 MeV) reactions. The evaporation residues were separated from the beam by using a gas-filled recoil separator and implanted onto a position-sensitive solid-state detector. The α-decay energies (half-lives) of197Rn,197mRn and200Fr have been determined to be 7261±30 keV (51 −15 +35 ms), 7370±30 keV (18 −5 +9 ms), and 7500±3O keV, (570 −140 +270 ms), respectively.